I just installed 2 wall caps for bathroom fans. After cutting out a 4" hole, the wall caps sat on top of the clapboards with big gaps behind it on part of the sides.

So I cut out the section of the clapboards for the 6 1/2" perimeter sides. Now the wall caps are flush against the plywood sheathing on the gable side of the house.

What if anything is recommend to be placed on top of the plywood sheathing behind the wall caps for weather protection, or some other reason that I should be aware of?

I was thinking of possibly tar paper, or another 1/2" layer of plywood, or ??

Thanks

joecaption

07-07-2012 04:15 PM

Post a picture of what you have done.
The siding was suppost to come off, a round hole big enough to have the vent slide in and be flush with the OSB with a hole saw. Nail the nailing fin then if it makes you feel better you can use Tyvek tape or seal sealing window tape around the flange. Then the siding goes back on.

There is another type of vent that is a flush mount but there's differant ones for every differant profile the siding comes in and they can only be mounted right at the lap in the siding. Main reason I just never use them is they look like poop, can leak, restricts where it can be mounted.